class A {
  constructor(a) {
    this.a = a;
  }
}

class B extends A {
  constructor(a, b) {
    super(a);
    this.b = b;
  }
}

let b = new B(1, 2);

//   console.log(b.__proto__)
//   console.log(b.__proto__.constructor)
//   console.log(B.prototype)
console.log(B.__proto__);
console.log(A.prototype);
console.log(A.__proto__);
